Arthurite - Encyclopedia
Class : Phosphates, arsenates, vanadates
Subclass : Hydrated Arsenates
Crystal System : Monoclinic
Chemistry : CuFe2(AsO4)2(OH)2 4H2O
Rarity : Very rare
Arthurite is a mineral with a complex structure, classified in the arsenates but comprising groups (PO4) and (SO4) in addition to (AsO4). It is a secondary mineral in the oxidation zones of copper deposits, usually formed by weathering of arsenopyrite or enargite. It was named in honor of the English mineralogist and collector Sir Edward Ian Montague Russel and the curator of the University of Oxford mineralogical collection Arthur William Gerald Kingsbury. Arthurite forms prismatic to acicular crystals not exceeding 4 mm, of a beautiful green color, frequently united in spherolites or in hemispherical aggregates with a fibroradiated texture.
Main photo : Arthurite from Majuba Hill Mine, Nevada, USA © Alex Earl
Arthurite in the World
Right photo : Arthurite from Cap Garonne, Var, France © Pierre Clolus
Twinning and special crystallizations
No twin known for this mineral species.
Fakes and treatments
No fake or treatment identified for this mineral species.
Hardness : 3 to 4
Density : 3.2
Fracture : Irregular
Trace : -
TP : Translucent to transparent
RI : 1.736 to 1.796
Birefringence : 0.060
Optical character : Biaxial (+/-)
Pleochroism : Weak
Fluorescence : None
Solubility : -
Magnetism : None
Radioactivity : None